Cervical dilator

ABSTRACT

A cervical dilator is provided which is adapted to be fully internally disposed during use. The cervical dilator comprises an expansible chamber defined by an elongated balloon-like member in which is disposed a laminary stick. A sealed capsule is also disposed in the chamber and contains water. The sealed capsule is adapted to be broken by applying pressure to the balloon-like member and contains a predetermined amount of water which will cause the laminary stick to swell to a desired final outer diameter.

United States Patent 1 [111 3,742,956 Loss 1 July 3, 1973 CERVICAL DILATOR 3,152,592 10/1964 Foley .1 128/349 B [76] Inventor: Michael Loss, 1879 Manor Drive,

Union, NJ 07033 Primary Examiner-Channing L. Pace Att0rneyLawrence l. Lerner et a1. [22] Filed: Aug. 18, 1971' A cervical dilator is provided which is adapted to be 2% 128/341 206/1316 fully internally disposed during use. The cervical dilad 4 tor comprises an expansible chamber defined by an 1 0 can 206/1316 30 elongated balloon-like member in which is disposed at laminary stick. A sealed capsule is also disposed in the chamber and contains water. The sealed capsule is [56] References Cited adapted to bebroken by applying pressure to the bal- UNITED STATES PATENTS loon-like member and contains a predetermined 241,569 5/1881 Stohlmann et a1 128/341 amount of water which will cause the laminary stick to 375,185 12/1887 Nichols et al 128/341 swell to a desired final outer diameter, 2,1 18,165 5/1938 Christopher et al.. 206/D1G. 30 UX 3,419,134 12/1968 Fitts 206/46 FC X 6 Claims, 8 Drawing Figures PAIENTEDJUL 3 I975 2 E D E: :':r \la 24 I52 FIG. 1

FIG. 3

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FIG. 6

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LERNER, DAVID 8 LITTENBERG ATTORNEYS CERVICAL DILATOR FIELD OF THE INVENTION The present invention relates to dilators used for medical purposes and particularly to a cervical dilator.

BACKGROUND OF THE INVENTION Dilators and similar devices are well known and have been used for many years as evidenced by U. S. Pat. No. 157,343 granted Dec. 1, I874 to W. Molesworth. Molesworth teaches a dilator which is expandable by a pump or the like which is disposed externally of the patient. As is brought out hereinafter, the present invention provides an expandable cervical dilator which is fully internally disposed during use.

The present dilator utilizes a breakable capsule or the like disposed within an expansible member and adapted to be broken when the member is to be expanded. The use of such a breakable member for expanding a catheter or the like is itself well known as evidenced by U. S. Pat. No. 3,152,592 granted Oct. 13, 1964 to F.E.B. Foley.

SUMMARY OF THE PRESENT INVENTION The present invention provides a cervical dilator which is adapted to be completely internally disposed during use. The cervical dilator is a completely selfcontained unit adapted to provide a desired amount of dilation at a desired rate. It is extremely simple to use, completely sanitary, disposable, easy to-insert, easy to remove, and performs in a manner that produces very little discomfort or pain to the patient, if any at all.

The preferred embodiment of the invention consists of an elongated balloon-like member composed of such a material and so constructed that it is adapted to exapnd substantially uniformly for a portion of its length when substantially uniform forces are applied to the internal wall of the balloon-like member. A laminary stick is disposed within the balloon-like member with one end adjacent one end of the balloon-like member. The stick provides a substantially rigid means for aiding in the insertion of the balloon-like member into the cervix. The preferred dilator finally comprises a water containing capsule disposed within the chamber and adapted to be broken upon application of pressure to a portion of the wall of the balloon-like member without rupturing the wall of the balloon-like member whereupon the released water will be absorbed by the laminary stick causing it to swell at a substantially predetermined rate in a substantially uniform manner. The uniformity of the final diameter of the cervical dilator along a certain portion thereof is realized by the interaction of the substantially uniform expansion of the laminary stick and the tendency of the balloon-like member to be expanded along its said predetermined length by the swelling laminary stick at a substantially uniform rate. 1.

Laminary sticks have been used for many years for the purpose of serving as cervical dilators. Laminary sticks may be made from slippery elm bark, privet, and eucalyptus strips. Though they are generally shaped by carving, cutting, and the like to provide a generally uniform diameter along their length as they expand, this usually is not achieved. The present invention provides a cervical dilator which utilizes the property of the laminary stick that it expands at a desired slow rate and is therefore much more comfortable for-the patient and, in addition, provides means for insuring that the final outer configuration of the dilator is substantially uniform. This is realized by the interaction of the wall of the balloon-like member with the laminary stick which tends to maintain a desired final outer perimeter of substantially uniform cross-section along a predetermined length, and the fact that a predetermined amount of water is employed. The use of the fully enclosed balloon-like member also prevents any problems of sterility of the laminary stick.

The present invention also comprises a completely self-contained expandable cervical dilator adapted to be completely internally disposed during use and which utilizes a gas to expand the balloon-like member. In such embodiments, a laminary stick need not be employed though a rigid elongated member must be employed to aid in the insertion of the cervical dilator.

Other preferred embodiments of the invention incorporate other additional features. For example, the rigid elongated member may be provided with an enlarged end portion adapted to engage the cervix upon insertion to provide an indication that the cervical dilator has reached a desired position. The cervical dilator may also be provided with protuberances on such enlarged portion for engaging the vaginal wall for retaining the cervical dilator in a desired position relative to the cervix during use. Still further, the cervical dilator may be provided with means for insuring that the water, in the case of the use of a liminary stick, will be substantially uniformly distributed along the stick to aid in the uniform expansion of the stick. These means may comprise a capillary tube, a groove in the stick, etc. Still further, the elongated rigid member may comprise a coiled material adapted to expand at a predetermined rate upon the absorption of water or the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a first embodiment of a cervical dilator in accordance with the present invention in which the balloon-like member is shown in cross-section for the purposes of illustration;

FIG. 2 is a cross-sectional view of the cervical dilator of FIG. 1 showing the cervical dilator after it has been fully expanded in which the balloon-like member is shown in cross-section for the purposes of illustration;

FIG. 3 is a side elevational view of a second embodiment of a cervical dilator in accordance with the present invention in which the balloon-like member is shown in cross-section for the purposes of illustration;

FIG. 4 is a side elevational view of the cervical dilator of FIG. Safter it has been fully expanded in which the balloon-like member is shown in cross-section for the purposes of illustration;

FIG. 5 is a side elevational view of a third embodiment of a cervical dilator in accordance with the present invention in which the balloon-like member is shown in cross-section for the purposes of illustration;

FIG. 6 is a side elevational view of a fourth embodiment of a cervical dilator in accordance with the present invention in which the balloon-like member is shown in cross-section for the purposes of illustration;

FIG. 7 is an end view of a laminary stick constructed in accordance with the present invention; and

FIG. 8 is an end view of an expandable elongated member in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The cervical dilator of the present invention generally comprises an elongated balloon-like member which defines a closed elongated expansible chamber, an elongated substantially rigid member disposed within the chamber, and a sealed breakable container disposed within the chamber and containing fluid forming means. The fluid forming means may comprise a liquid, such as water, when the elongated rigid member is of the type which will swell when brought into contact with the liquid and thus expand the balloon-like member at a desired predetermined rate to substantially a desired predetermined size. The fluid forming means may also comprise means for forming a gas which will expand the balloon-like member at a desired rate to substantially a desired predetermined size. In such cases, the substantially rigid member would only serve the function of aiding in inserting the dilator and not the second function of effecting the desired expansion. Also, when utilizing a gas, one is selected which will slowly expand the balloon-like member so that it reaches its desired maximum dilation in from 2 minutes to approximately 2 hours. Of course, longer and shorter times may be provided and may prove to be desirable in certain cases.

Referring now to the drawings in which like refer- .ence numerals refer to similar parts throughout, a first embodiment of a cervical dilator 10 in accordance with the invention is shown in FIGS. 1 and 2. Dilator 10 comprises a fluid impervious elastic balloon-like member 12 which defines a fully enclosed elongated chamber 14. An elongated laminary stick 16 is disposed within chamber 14 adjacent the inserting end 18 of dilator 10. A water containing breakable capsule 20 is ,disposed within chamber 14 adjacent its other end. Water containing capsule 20 may take many forms. For example, a separate fluid containing chamber may be formed within chamber 14 by providing a breakable diaphragm which initially would seal off a portion of chamber 14. In the presently illustrated embodiments, capsule 20 is similar to the capsules shown in the aforementioned Foley patent.

Laminary stick 16 is substantially cylindrically shaped. The water contained in capusle 20 will cause laminary stick 16 to swell at a rate dependent both upon the material from which the laminary stick has been made and the amount of water contained in member 20.

Laminary stick 16 is, preferably, from approximately two centimeters to approximately six centimeters long. Thus, laminary stick 16 is sufficiently long so that it can be used for grasping of the dilator l and inserting same so that the portion of the dilator containing the laminary stick I6 is disposed within the cervix uteri. It is sufficiently short so that there is little danger of perforating the wall of the uterus when inserting dilator into the cervix uteri.

Laminary stick 16 because of its uniform shape will expand in substantially a uniform manner. However, there is usually some differential in the swelling of the stick in that the end 24 will normally expand more rapidly than the end 26. This is desirable in that such a final shape facilitates removal of thedilator 10 but can prove to be uncomforatable if the difference in expansion is unduly great. In order to avoid such discomfort due to the non-uniform expansion of laminary stick 16, elastic member 12 is so constructed that it tends to expand in a substantially uniform manner. In addition, it is so constructed that it will expand to a substantially constant predetermined diameter. This is achieved by selection of a desired elastic material which is constructed to and will expand to a predetermined final diameter even when the forces generated are somewhat greater than is required. Mylar, vinyl material, etc. can be employed. It is also necessary that a sufficient thickness of the material be used so that it will not rupture upon breaking of capsule 20.

A second embodiment of a cervical dilator 30 in accordance with the present invention is shown in FIGS. 3 and 4. Dilator 30 contains a fluid containing capsule 20 and a liminary stick 32 having an enlarged end portion 34. The dilator 30 when in its contracted state is just slightly larger than the cervical opening. When inserting dilator 30 into the cervix uteri, one can sense when enlarged end portion 34 abuts against the mouth of the cervix which is therefore indicative of the fact that dilator 30 is in its desired operative position.

A third embodiment of a cervical dilator 40 in accor dance with the present invention is shown in FIG. 5. Dilator 40 comprises a capsule 20 and a laminary stick 42. Laminary stick 42 has an enlarged end portion 44 which has projections 46. The protuberances 46 are disposed at an angle such that they project in a direction away from the inserting end 18 of dilator 40. The protuberances 46 are so shaped that they tend to engage the wall of the vagina when dilator 40 is properly inserted thus retaining dilator 40 in a desired position relative to the cervix uteri and the vagina.

A fluid distributing member 48 is disposed adjacent laminary stick 42. Fluid distributing member 48 is in the form of a capillary tube which has holes (not shown) along its length which will insure that water will be disposed along laminary stick 42 and at the end 50 of laminary stick 42 when enlarged end portion 44 swells to such an extent that it would normally tend to block passage of fluid past it.

FIG. 6 is a side elevational view of a fourth embodiment of a cervical dilator S4 in accordance with the present invention. The balloon-like member 12 is shown in its expanded state. This expansion was affected by the formation of a gas when capsule 20 was broken open as is well known from the aforementioned Foley patent. The elongated substantially rigid sticklike member 56 is of the type that will not expand when capsule 20 has been broken. Thus, member 56 serves the sole purpose of aiding in the insertion of dilator 54 while the previously illustrated laminary sticks serve I this function plus the additional function of cooperating with the fluid in the capsule 20 to produce substantially uniform forces against the inner walls of their respective balloon-like members to effect the desired substantially uniform expansions thereof.

FIG. 7 is an end view of a laminary stick 60 in accordance with the invention. Laminary stick 60 has an elongated groove 62 extending along its entire length. The groove 62 acts as a means for equally distributing fluid along the length of laminary stick 60. Thus, it serves as a channel for the fluid. This could also be accomplished by, for example, providing a hole centrally of laminary stick 60.

It will be appreciated that the elongated substantially rigid members all serve as a means for aiding in the insertion of the dilators. In addition, some serve to provide the desired uniform expansion. As indicated, laminary sticks can satisfactorily effect both of the foregoing desired functions. It is also possible that certain plastic or cardboard materials or the like may be found which can satisfactorily provide both functions. One example of such a member is the coiled plastic elongated substantially rigid member 72 shown in FIG. 8. Member 72 is of the type which will uncoil at a predetermined substantially uniform rate to a desired final diameter when contacted by a fluid which can be contained in a capsule such as the capsules illustrated in FIGS. 1 through 6 of the drawings.

The above description has been by way of example only and has not been intended as a limitation to the scope of the invention as defined in the appended claims.

What is claimed is:

l. A cervical dilator comprising a closed expansible chamber defined by an elongated balloon-like member which is adapted to expand to produce a substantially cylindrical portion having a substantially uniform predetermined final diameter when substantially uniform forces at least sufficient to expand the balloon-like member to its substantially predetermined final diameter are applied to the inner wall of the balloon-like member, a laminary stick having a substantially uniform diameter along at lesat a major portion of its length, which length isshorter than the total length of said chamber and is fully disposed within said chamber, and a sealed breakable fluid containing means disposed within said chamber and adapted to be opened by the application of pressure in a particular manner to the balloon-like member, said fluid containing means containing a liquid and said laminary stick being adapted to absorb said liquid, thereby causing said laminary stick to swell, thereby causing said balloon-like member to expand.

2. A cervical dilator according to claim 1, wherein said laminary stick has an enlarged end portion adapted to engage the cervix when the cervical dilator is in a desired position relative to the cervix.

3. A cervical dilator according to claim 2, wherein said enlarged end portion comprises projections adapted to aid in the holding of the cervical dilator in its desired position relative to the cervix by engaging the vaginal wall.

4. A cervical dilator according to claim 3, wherein said laminary stick comprises an elongated groove disposed longitudinally of and along its outer periphery, said groove being of a sufficiently shallow depth such that the cylindrical outer diameter of said laminary stick is not substanitally disturbed and being sufficiently deep enough to permit the flow of liquids therealong during expansion of said laminary stick.

5. A cervical dilator according to claim 1, further comprising means for uniformly distributing said liquid longitudinally of said laminary stick during expansiom of said laminary stick.

6. A cervical dilator according to claim 1, wherein said laminary stick comprises an elongated groove disposed longitudinally of and along its outer periphery, said groove being of a sufficiently shallow depth such that the cylindrical outer diameter of said laminary stick is not substantially disturbed and being sufficiently deep enough to permit the flow of liquids therealong during expansion of said laminary stick. 

1. A cervical dilator comprising a closed expansible chamber defined by an elongated balloon-like member which is adapted to expand to produce a substantially cylindrical portion having a substantially uniform predetermined final diameter when substantially uniform forces at least sufficient to expand the balloon-like member to its substantially predetermined final diameter are applied to the inner wall of the baLloon-like member, a laminary stick having a substantially uniform diameter along at least a major portion of its length, which length is shorter than the total length of said chamber and is fully disposed within said chamber, and a sealed breakable fluid containing means disposed within said chamber and adapted to be opened by the application of pressure in a particular manner to the balloon-like member, said fluid containing means containing a liquid and said laminary stick being adapted to absorb said liquid, thereby causing said laminary stick to swell, thereby causing said balloon-like member to expand.
 2. A cervical dilator according to claim 1, wherein said laminary stick has an enlarged end portion adapted to engage the cervix when the cervical dilator is in a desired position relative to the cervix.
 3. A cervical dilator according to claim 2, wherein said enlarged end portion comprises projections adapted to aid in the holding of the cervical dilator in its desired position relative to the cervix by engaging the vaginal wall.
 4. A cervical dilator according to claim 3, wherein said laminary stick comprises an elongated groove disposed longitudinally of and along its outer periphery, said groove being of a sufficiently shallow depth such that the cylindrical outer diameter of said laminary stick is not substantially disturbed and being sufficiently deep enough to permit the flow of liquids therealong during expansion of said laminary stick.
 5. A cervical dilator according to claim 1, further comprising means for uniformly distributing said liquid longitudinally of said laminary stick during expansion of said laminary stick.
 6. A cervical dilator according to claim 1, wherein said laminary stick comprises an elongated groove disposed longitudinally of and along its outer periphery, said groove being of a sufficiently shallow depth such that the cylindrical outer diameter of said laminary stick is not substantially disturbed and being sufficiently deep enough to permit the flow of liquids therealong during expansion of said laminary stick. 